Sutures of the Skull

Sutures are immovable joints that appear as irregular lines or seams between the skull bones.

These fibrous joints consist of dense connective tissues composed of collagen fibers.

However, the infant skull has fontanelles — soft areas which are flexible to accommodate the rapidly growing brain.

During development, these fontanelles ossify, become hard, and close, eventually forming the complete sutures as seen on an adult skull.

Of the four prominent sutures, the coronal suture interlocks frontal and parietal bones. The sagittal suture joins the paired parietal bones to each other.

As seen from the lateral side, the lambdoid suture unites the occipital and parietal bones.

On both lateral sides of the skull, the squamous suture connects the temporal and parietal bones.

Numerous other sutures are visible on the skull, named according to the bones they unite. For example, as seen on the anterior side, the frontal and nasal bones join at the frontonasal suture, while the frontozygomatic suture joins the frontal and zygomatic bones.